Tube-forming machine.



Patented Apr. 11, 1916.

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xr wim Y w Y lwi Y is a specification.

UNITED STATES PATENT OFFICE.

i MARSHALL BURNS LLOYD, 0F MENOMINEE,

MICHIGAN, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE ELYRIA IRON 6c STEEL COMPANY, 0F ELYRIA, OHIO, A CORPORA- TION OF OHIO.

TUBE-FORMING MACHINE.

application inea uayie, i913. seriai Na 768,539.

To allie/wm it may concern: 1

Be it known that I, MARSHALL LLOYD, a citizen of the United States, and a resident of Menominee, iii the county of Menominee and State of AMichigan, have invented certain' new and useful Improvements in Tube- Forming Machines, of which the'following My invention relates generally to mechanism for forming tubing, and has particular reference to mechanism for 'formingtuhing lfrom strip metalfstock. y

The general object of my invention is'to provide mechanism for making tubing from strip stock in such manner that the tube seam will remain closed after emerging from the forming mechanism;

Another object of my invention is to pro- A vide a mandrel for use in'tiibe-forming maoperation of the chinery which shall act iii conjunction therewithto set the tube edges permanently together and if desired withoutredu'cing Athe thickness of the metal; and a further-object is to provide a .mandrel for `use in tubeforming mechanism which shall act with minimum frictional contact with .the tube, to the end that the mechanism may lie-operated 'with minimum power; vthat the life of the mandrelmay be increased; and `that tubing may be made continuouslyV with little attention.

My invention consists generally in the unique construction, arrangement, and coparts whereby those objects i named above, as well as others which will appear hereinafter` are attained.

My invention will'be more readily understood by reference to the accompanying drawings, which illustrate the preferred form of my invention, and in which:

Figure 1`is a plan view of mechanism embodying my invention; Figs. 1, l", 1, and f 1' are detail vviews illustrating the evolution from a strip metal to that-of a completed tube;.Fi g. -2 is substantially a longi-L tudinal vertical section on the line 2 2 of Fig. 1; Fig. 3 is a perspective view of the mandrel used in conjunction with the Atube forming rolls; Eig. 4. is an enlarged side elevation of. the liead portion of the mandrel; Fig 5 is :i plan view thereof; Fig. 6 is a cross sectional view substantially on the line 6 6 of Fig. 4 showing themanner of housing the rolls; F ig.'7 is a fragmentary view in elevation of one-half of the mandrel Specification Letters Patent.

Fig 8 is a view.,

Patented Apr. 11, 1916 head .showing the roll-receiving cavities;-A

similar to Fig. 7, but showing roll-receiving recesses of modified-form; and Figs. 9 and 10 are respectively enlarged fragmentary views showing the operation of the mandrel with the final forming rolls.

For many purposes it is desirable and necessary to provide tubing having the seam tightly closed. For example, when making tubing from strip stock to bejwelded it is desirable to have the seam tightly closed in order that the welding flame will not cut through the seam and spoil the tubing, It is also .desirable to have the ends of the tube, cross-sectionally considered, abut in manner to form a smooth joint at the seam, e., to keep the ends from overlapping orprojecting above or'below'the adjacent end. These desired features, however, should not be attained at the expense of greatly reducing the thickness of the metal or of requiring tremendous power and much labor. y

I shalljnow describe in detail my unique mechanism whereby tubing, With tightly closed seams, can be manufactured from strip stock with minimum amount of labor,

first form. These comprise upper and lower` rolls al and u? which are slidably mounted in standards a. The rolls are vertically .adjustable by mea-ns of adjusting screws a4.

This tube-forming mechanism is well adapted for and is much'usediii the continuously making of tubing from strip stock and 1sparticularly adapted for forming the metal intotubes iu condition for welding. The

stril;` metal C is usually fed 'from a. largev reel not shown) and enters the initial form- 'i ing mechanism A through a guide G. The guide G is adjustable to accommodate various widths-of strip stock and "cf course by providing different sized forming mecha- ,nisnis, ,tubes of various diameters can'be made. The strip stock is shown in Fig. 1a as it enters the first forming mechanism and in passing therethrough assumesthe shape indicated in Fig. 1b. The strip enters'the final forming mechanism B and emerges therefrom in the form of a tube having a4 seam which is tightly closed. After its emergence from the final forming mechanism B, I often perform one or more operations upon it, but they are in no wise essential to the present invention. I usually provide some sort of draft mechanism such, for instance, as the continuous vise E, shown in my Patent No. 1,027,865 of May 28, 1912. I have not shown the draft mechanism here inasmuch as any suitable draft mechanism will suffice, or in lieu of a separate mechanism to draw the strip through the forming mechanism, A and B, I may drive either or both sets of rolls constituting the forming mechanism. I prefer, however, to drive the initial forming rolls A and to depend upon the same to force the strip through the final forming mechanism B either independently or in conjunction with a separate draft mechanism such as before mentioned. For purposes of driving the rolls al and a2, I provide the upper and the lower shafts a5 and a respectively with intermeshing gears a7 and drive one of the shafts from any suitable source of power by means of the belt and pulley a8.

The final forming mechanism here shown comprises a `plurality of pairs of horizontally arranged forming rolls b1, b2, and b", mounted in a frame B1 rising from and secured to the table Z. The rolls are mounted in journal boxes b, which are slidably held in the frame B1, being adjustable by means of screws b". The rolls b1, b2, and b3, are provided with different shaped grooves b, Z, and b, and they serve gradually to form the strip metal from the shape indicated in Fig. 1b of the drawings to that of a substantially finished tube, as indicated in Fig.

f". The last set of rolls b8 and b9 are preferably mounted for rotation Ain vertical planes and are held in vertically adjustable boxes b1 slidably arranged in the standard portion, B3, of the frame and are adjustable by means of screws b, and b1?. They contain grooves b13 and b, the shape of which is dependent upon the desired form of tube. In this instance I desire to make a circular tube and have therefore made 'the grooves substantially semi-circular in shape. The'rolls b3 and b9 would in and of themselves serve to shape the strip metal as it is forced therethrough `to substantially the shape of the combined recess, but so soon as the tubing would emerge from the rolls bs and b9 the resiliency of the metal would cause the seam to open.v As before stated, it is one ofthev objects of my invention `to provide mechanism for making tubing with a permanent set as it passes therethrough.'-

This mechanism consists of a mandrel D of unique construction, which comprises a head-` portion d and a shank portion or tension rod d. 'Secured to one end of the shank portion d2 is an upstanding member d3 which is secured to a block d* carried by the frame B1. The mandrel, as shown in Fig.

v2, extends from a point adjacent the initial forming rolls A, where the strip is only partially formed, into the tube and forwardof the rolls bB and b9. In order that I may accurately adjust the position of the head d1, which coperates with the forming rolls bs and b9, I secure the block d, carrying the mandrel, adjustably to the frame B,1 by means of the elongated slots 0l and the stay bolts d6 arranged therein. Although the mandrel head may be placed to cooperate with the rolls slightly on either side of or in the center of the rolls, I prefer to place it so that the coperating portion will be slightly forward of the center of the rolls.

In the continuous formation of tubing with the ordinary form of mandrel, considerable friction is produced by engagement of the mandrel with the inner surface o'f the tubing and this is augmented when it is vattempted to force the ends of the tubing, cross-sectionally considered, together in order to `close the seam permanently. This excessive friction causes the mandrel Kto gather dirt and foreign matter from the metal and also causes it to scrape off a portion of the inner surface of the tube, thereby reducing in a measure the thiclniess of the metal. AThe mandrels now in general use, when subjected to such treatment, require frequent cleaning and also soon wear out. These conditions make it extremely difficult to produce tubing continuously from strip stock, in which the seam is tightly closed, which is of uniform size and which is not materially reduced in thickness by its passage through the forming mechanism. These objectionable by my unique mandrel. I provide the head portion d1 of the mandrel with rolls d and dV which roll one upon the other and which together are slightly greater than the thickness of the head portion. These rolls engage the inner surface of the tubing and serve to distort it in manner toclose the seam. The action of the rolls d and d will be best understood by reference to Figs. 2, 9 and 10. Fig. 9 is an enlarged detail sectiona Jiew of the tubing slightly to of the rolls. The tube T, as there indicated, conforms substantially to the grooves b and Il, respectively, of the upper and lower rolls. The curvature of' the `recess b in the lower roll, however, is slightly more features are overcome the left of the center acute than that of the upper roll and of the tubing, thereby forming a small space b15 between the lower side of the tubing and the upper portion of the lower forming roll. The seam t, as defined by the end portions t1, t2 of the tube, is substantially closed, but,

as before stated, if the tube were not treated further, upon emerging from the rolls bs and b9, the portions t1 and t2 would spring away, thereby opening the seam. I overcome this by forcing the portion t3 of the tube downwardly, as indicated at 615', to close the space b5,thereby throwing the portions tl, t2 of the tube tightly together. This action is best shown in Figs. 2 and 10 of the drawings, where it will be seen that the upper and lower rolls ds and d", acting together, firmly press the metal into conformity with the grooves of the upper and lower rolls. For the sake of convenience, I shall term this operation distorting the tube to close the seam. Now when the tube emerges from the forming rolls, the seam will remain tightly closed, as indicated in Fig. l". I have considerably exaggerated the deforming effect of the mandrel upon the tube in Fig. 1x in order that the idea may be readily understood.

Another advantage to be derived from the use of my mechanism, is that the pressure of the rolls against the tubing, as indlcated 1n Fig. 10, serves to bring the end portions of the tube t1 and t2 exactly into line, that is, form them so that they match and do not overlap, nor do they extend above or below each other. This is a valuable feature, inasmuch as it provides a tube of neat appearance and increased strength,v but is particularly valuable when the tubing is to be welded, since the flame playing upon the portions of the tube adjacent the seam will heat them uniformly and when the pressure is applied a weld of greater strength is attained. The tube also is in better shape for finishing, if the same is desired,than it would be if the joint were not smooth.

By properly shaping and proportioning the upper and lower rolls of the mandrel I can slightly decrease the thickness of the tube just at the bottom enough to force the metal into the side portions of the tube (cross sectionally considered) and thereby close the seam. Ordinarily, however, I prefer not to reduce the thickness of the tube at any place but to close the seam as before described by slightly distorting the tube.

The head portion of the mandrel comprises two substantially semi-cylindrical portions d and d which are secured together by binding screws d. The shank or tension portion d2 of the mandrel is-secured to the head portion by the screws d. I provide recesses d in the portions d" and d" to which the rolls substantially conform and in which'they are rotatably held. The head is cut away, as indicated at d and d, to expose the portions of the upper and lower rolls. In order that the rolls may be easily lubricated, I provide a groove 23 in the upper portion of the mandrel shank which communicates with a groove d of the mandrel head and by inclining this groove slightly to the rolls, they maybe readily lubricated. It is obvious that the frictional engagement between the mandrel and the tubing is greatly minimized by the provision of these rolls, and, as before stated, that the rolls serve the further function of distorting the tube for the purpose of giving it a permanent set. My unique mandrel may be used continuously for a great length of time and will enable the production of uniformly sized tubing. Further, when necessary, the working parts can be easily repaired and cleaned.

I have shown a modified form of mandrel in Fig. 8. In this case, instead of making the recesses in the mandrel head to conform substantially to the rolls, they are formed to provide only lines of contact with the rolls. I accomplish this by forming recesses having flat defining walls d so that the rolls, as indicated in dotted lines, engage the same only along the center lines of the sides. In this manner the frictional contact of the rolls with the head is decreased.

The mechanism herein shown and described serves admirably to accomplish the objects sought for, but since this disclosure will suggest to others skilled in the art, modified structures adapted to accomplish substantially the same objects, I do not wish to limit my invention to the specific construction and arrangement herein shown and described.

I claim:

1. A mandrel for tube-forming machines comprising a tension rod portion and a head portion, said head portion consisting of two substantially semi-cylindrical parts, two contiguous recesses in each sai'd semi-cylindrical part of the head portions, means for assembling the two semi-cylindrical por- I tions with the recesses thereof alined, antifriction rollers arranged in said recesses, the head portion being cut away to expose a ortion of each roll, and a groove leading rom the tension rod portion to the antifriction rolls.

2. In a tube forming machine, a plurality of pairs of dies, for bending strip material to substantially circular form in combination with a mandrel positioned to coact with one pair of dies, opposed rolls in said mandrel, the said co-acting dies having a section which differs from the semi-circular section of the tubing by being somewhat more curved, thus forming` a s ace to perdeformation of the tube y the said ro 3. The herein described improved means for converting an outwardly resilient and hence open butt-seamed tube into an inwardly resilient and hence tightly closed butt-seamed tube, colnprising an external die composed of opposed rolls presenting a die opening substantially conforming to the cross section of the outwardly resilient tube, in combination with a mandrel of greater effective diameter than the outwardly resilient tube but of less width, said mandrel being positioned Within said die and tube and acting to hold the seam edges of the tube and `distorting the tube opposite said seam edges.

4. The herein described improved means for converting an outwardly resilient and hence open butt-seamed tube into an inwardly resilient and hence tightly closed butt-seamed tube, comprising an external die composed of opposed rolls presenting a die opening substantiallv conforming to the cross section of the outwardly resilient tube, in combination with a mandrel of greater effective diameter than the outwardly resilient tube but of less width, the greatest diameter of said mandrel being marked by anti-friction rolls and said mandrel being positioned within said die and tube and the anti-friction rolls thereof acting to holdthe seam edges of the tube while distorting the tube opposite the seam.

In testimony whereof, I have hereunto set my hand this 8th day of May, 1913, in the presence of two subscribing witnesses.

MARSHALL BURNS LLOYD.

lVitnesses ARTHUR W. NELSON, M. SIMON. 

